<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>页面渲染性能优化</title>
  <style>
    body{
      background: gray;
    }
  </style>
  <link href="https://cdn.bootcss.com/twitter-bootstrap/4.4.1/css/bootstrap-grid.css" rel="stylesheet">
  <script>
    performance.mark('css done')
  </script>
</head>
<body>
  <div id="app">
    121212
    <script>
      performance.mark('text done')
    </script>
  </div>
  <script src="./src/2.fmp.js"></script>
</body>
</html>